The present disclosure relates generally to information handling systems, and more particularly to a layer 3 routing loop prevention system for information handling systems.
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems such as, for example, switches or routers, are utilized in directing data traffic through networks. In some situations, multiple devices may be used to provide a logical switch that is used to direct data traffic. For example, a plurality of control bridge devices may be coupled to a plurality of port extender devices to provide a logical switch such as, for example, per the Institute of Electrical and Electronics Engineers (IEEE) 802.1BR standard. In some scenarios, links between the control bridge devices and/or port extender devices may be aggregated. In such aggregated link situations, the failure of one or more aggregated links can create issues that result in layer 3 routing loops. For example, a port extender device may be coupled to two control bridge devices via a first Link Aggregation Group (LAG) that includes a first link to a first control bridge device and a second link to the second control bridge device, and the first and second control bridge devices may be coupled together via a second LAG (sometimes referred to as an Inter-Chassis Link (ICL)). When the first link in first LAG to the first control bridge device fails, the first control bridge device may failover to a backup path that results in the first control bridge device forwarding traffic destined for the port extender device over the second LAG to the second control bridge device, and the second control bridge device forwarding that traffic to the port extender device over the second link. Similarly, when the second link in first LAG to the second control bridge device fails, the second control bridge device may failover to a backup path that results in the second control bridge device forwarding traffic destined for the port extender device over the second LAG to the first control bridge device, and the first control bridge device forwarding that traffic to the port extender device over the first link.
However, if both the first link and the second link in the first LAG fail or are otherwise unavailable at the same time, such failover behavior may be enabled in both the first control bridge device and the second control bridge device. As such, the first control bridge device may failover to the backup path that results in the first control bridge device forwarding traffic destined for the port extender device over the second LAG to the second control bridge device, the second control bridge device may failover to the backup path that results in the second control bridge device forwarding that traffic back over the second LAG to the first control bridge device, and so on until the time to live (TTL) of the traffic reaches zero. During the time until the TTL reaches zero, the traffic will loop between the first control bridge device and the second control bridge device, using bandwidth of the second LAG and reducing the bandwidth of the logical switch.
Accordingly, it would be desirable to provide a layer 3 routing loop prevention system.